Gripping device for tubes of heatexchange apparatus



NOV. 2, 1937. 2,097,683

GRIPPING DEVICE FOR TUBES OF HEAT EXCHANGE AFPARATUS R. ARMSTRONG Filed July 31, 1956 R A E o i h E m C\ W N l B Robezfl Awtrong Patented Nov. 2, 1937 ATENT OFFlCE GRIPPING DEVICE FOR TUBES EXCHANGE APPARATUS F HEAT- Robert Armstrong, Itidgefield, N. J. Application July 31, 1936, Serial No. 9 3,621 5 Claims, (Cl. 294 -92) My. present invention relates generally to tools, and has particular reference to a gripping device for eiiternally engaging a tube of a heat-exhanseappa atu It is a general object'of my invention to provide an improved tool Whose employment facilitates and speeds up the removal of tubes from a heatexchange apparatus, during the process of overhauling the latter.

For the purpose of explaining the nature and purposes of my present invention, I will point out that a surface condenser is a typical example of the kind of heat-exchange apparatus whose servicing is simplified by means oi"- the present tool. It is well known that a surface condenser comprises a series of tubes arranged in a parallel group and supported at their ends by two tube sheets, each or" which forms the inner wall of a chamber. Water is usually directed into the bottom of one chamber, passing thence through certain of the tubes to the other chamber, and thence back through other tubes to the first chamber, and out. After a certain period of use, the tubes are likely to become worn and corroded and have to be replaced. It is not unusual for the-tubes to be as much as twenty feet long, and sometimes longer; and many thousand tubes are customarily arranged in close proximity in a single heat-exchange apparatus.

In my Patent Number 1,717,487, issued June 18, 1929, I have described a tube-pulling tool which may be applied to one end of a tube of the character mentioned to grip the tube from within and thereupon to impart a forceful yank to the tube to displace the same from the tube sheets. In employing a pulling device of this character, the initial yank is usually sufiicient to permit a single workman thereafter to pull the tube by hand lengthwise out of its position. It frequently happens, however, thatthe tube resists easy withdrawal, by, virtue either of burring at the remote end of the tube, or because of the passage of the tube through certain intermediate supporting plates, or for other reasons. Furthermore, it is frequently impossible to continue the use of the patented tube-pulling tool because of lack of space.

The specific object of my present invention is to provide an improved gripping device which may be applied externally over a tube of the character mentioned, after the same has been initially displaced from the tube sheet in which it is mounted, the present gripping device permitting the application of mechanical or pneumatic force to permit the grippedand stubborn tube to be fully withdrawn from the heat-exchange apparatus.

My present tool is characterized by a complete absence of moving parts, by its extreme simplicity of structure and operation, and by its high ,5 efficiency in firmly and reliably engaging the tube thatis to begripped and pulled.

Briefiy, the 'present tool consists of ,a pair of jaws which are shaped and spaced to perlrlit pas sage between themof the tubeto be grippedlthe A0 jaws being mounted in'afcarriei which is providedavith a portion adapted to receive a pulling force applied in a directionsubstantially parallel to but offset from the axis of'the gripped tube,

Afeature of "my invention lies in the provision 1.6 of parallel carrier arms which engage the jaws between them, together with releasable means for retaining the jawsand said armsjin fixed relationship, Another feature lies in provid n means for adjusting the jaws individually relative to the carrier, thereby permitting renewal of the grippingsurfaces which are presented towardeach other.

A characterizing feature of the inventipn lies in oonstructingllfinclijaw the formlof amemher having substantially the shape of a hyperboloid.

Th p s nt t m be a nts v be nesse of the come-along variety,sin'ce it "maybe shifted from place to place along the tube during the movement of. the latter. I achieve the foregoin objects, and such other objectsas may hereihaiter, appear or be pointed out, in the manner illustratively "exemplified in th a mp in rewinaw e Figure l is a View, partly in cross-section,

showing the manner in which the present ool is applied to a tube which isabout to be removed from a heat exchange apparatus} Figure 2 is a cross-sectional view taken sub- 40 stantially along the line 2- 2 of Fig llf el and Figure 3 is a perspectiveyiew of the present tool by itself. a

In Figure 1, I have indicated at H! a typical tube sheet within which a multiplicity of tubes .45 H are mounted. I have illustratively s own" a portion of. a'heat-exchange apparatus infwhich the tubes are belled at theirbuter ends to secure them, in fixed relationship'to the tube sheet. In the upper portion of" Figure 1, I show a' tube i i in its normal disposition within the tube sheen H]. In the lower portion of Figure l, I have shown a tube H which has been initially yanked out rthe tube sheet, preferably with the aid, of a tube-pulling device of the character illustrated and described in my aforementioned Patent Number 1,717,487.

The initial displacement of the tube from the tube sheet positions the end of the tube about three to six inches beyond the surface of the tube sheet. While, ordinarily, such a displaced tube may be withdrawn endwise, by purely manual effort, it frequently happens that a greater force is required to withdraw the tube from the heat-exchange apparatus. In such an event, a gripping device of the present type may be applied over the end of the tube, as shown most clearly in Figure 1.

Referring for the moment to Figure 3, the present device consists of a pair of jaws I2 and I3, each of which preferably consists of a member having substantially the shape of a hyperboloid. The curved hyperboloidal surfaces are roughened, so that the jaws present toward each other twogconcavo-convex gripping surfaces adapted to accommodate the tube between them, as shown most clearly in Figure 2.

' The jaws are made of any suitable material, preferably tool steel, and they are mounted in a jaw carrier which consists of the spaced parallel arms l4 and I5. These arms have one set of ends 16 and I1 bentinto contiguous relationship and shaped, preferably, to form a loop or ring 18.

This loop portion of the carrier is adapted to receive a pulling force, and I have illustratively shown the manner in which a cable l9 may be' engaged within the loop l8. This cable may extend from any suitable source of power, either mechanical, pneumatic, or otherwise, and I have not'illustrated the power source because it forms no part of the present invention. It will be understood, however, that the pulling force is applied to the present tool in a direction substan tially parallel to, but offset from, the axis of the tube which is gripped. 'The application of this force positions the present tool in the oblique relationship shown in Figure 1, thereby insuring a firm engagement of the tube. As a matter of fact, the firmness of engagement of the tube increases with the increase of force in the direction of the arrow of Figure 1.

In accordance with my invention, means are provided for permitting adjustment of the jaws relative to the carrier to permit renewal of the operative gripping surfaces from time to time. In the preferred embodiment, the jaw 13 carries at each end a lug 2! which is of equilateral polygonal cross-section. I have illustratively shown a sq'uare'lugin each case. The carrier arms I4 and I5 are each provided with a correspondingly shaped aperture into which the lugs 2| snugly fit. The jaw I2 is similarly provided with lugs 22, of similar or equivalent shape, these lugs fitting into apertures purposely provided in the carrier arms l4 and I5. 7 To hold theparts in fixed assembled relationship, the lug's.2l carry threaded bolt portions 23, adapted to receive tightening nuts 24,

The manner of use of the present tool will be obvious to those skilled in the art. The tool is applied endwise over the projecting end of the tube II, the space between the jaws being sufficient to permit passage over the belled end of the tube, or over any packing or other projecting material. An external force is then applied to the force-receiving portion l8, and this causes a firm engagement of the tube ll between the gripping surfaces of the jaws, as shown in Figures 1 and 2. ,If, during the withdrawal of the tube, it is necessary to shift the position of the present tool, it

is a relatively simple matter to discontinue the pulling force momentarily and to shift the tool bodily along the tube which it has been gripping. Ultimately, the withdrawal of the present tool from either one or the other end of the tube I l is a relatively simple matter.

In the event that it is desired to renew one or both of the operative gripping surfaces of the jaws, or in case the jaws need complete replacement, it is merely necessary to remove the nuts 24. This permits the two carrier arms to be separated one from the other, and the two jaws are then easily removable. If they are merely to be rotatively adjusted, the polygonal cross-section of the lugs 2| and 22 permits this adjustment to be effected with facility.

In general, it will be obvious that changes in the details, herein described and illustrated for the purpose of explaining the nature of my invention, may be made by those skilled'in the art without departing from. the spirit and scope of the invention as expressed in the appended claims. It is, therefore, intended that these details be interpreted as illustrative, and not in a limiting sense.

Having thus described my invention, and illustrated its use, what I claim as new and desire to secure by Letters Patent is- 1. A gripping device for externally engaging a tube of a heat-exchange apparatus, comprising a pair of jaws shaped and spaced to permit passage between them of the tube to be gripped, and a jaw carrier provided with a portion adapted to receive a pullingforce applied in a direction substantially parallel to but offset from the axis of the gripped tube, each jaw consisting of a member having substantially the shape of a hyperboloid.

2. A gripping device for externally engaging a tube of a heat-exchange apparatus, comprising a pair of jaws shaped and spaced to permit passage between them of the tube to be gripped, and a jaw carrier provided with a portion adapted to receive a pulling force applied in a direction substantially parallel to but offset from the axis of the gripped tube, each jaw consisting of a member having substantially the shape of a hyperboloid, the hyperboloidal surfacesbeingroughened so that the tube is firmly gripped between the two opposed gripping surfaces.

3. A gripping device for externally engaging a tube of a heat-exchange apparatus, comprising a pair of jaws shaped and spaced to permit passage between them of the tube to be gripped, a jaw carrier provided with a portion adapted to receive a pulling force applied in a direction substantially parallel to but offset from the axis of the gripped tube, each jaw consisting of a member having substantially the shape of a hyperboloid, and means for adjusting the jaws to present different portions of their surfaces toward each other.

4. A gripping device for externally engaging a tube of a heat-exchange apparatus, comprising a pair of jaws shaped and spaced to permit passage between them of the tube to be gripped, a jaw carrier provided with a portion adapted to receive a pulling force applied in a direction substantially parallel to but offset from the axis of the gripped tube, each jaw consisting of a member having substantialy the shape of a hyperboloid, and means for adjusting the jaws to present different portions of their surfaces toward each other, said means comprising spaced parallel carrier arms having apertures of equilateral polygonal shape, and each jaw having a lug of corre- 'sponding cross-sectional shape for engagement in one of said apertures.

5. A gripping device for externally engaging a tube of a heat-exchange apparatus, comprising a pair of jaws shaped and spaced to permit passage between them of the tube to be gripped, a jaw carrier comprising spaced parallel arms adapted to engage the jaws between them, said carrier having a portion adapted to receive a pulling force applied in a direction substantially parallel to but ofiset from the axis of the gripped tube, each jaw consisting of a member having substantially the shape of a hyperboloid, and means for adjusting the jaws relative to the carrier to permit renewal of the gripping surfaces which are presented toward each other, said means comprising a lug on each jaw of equilateral polygonal cross-section, an aperture of corresponding shape in one of said carrier arms, and releasable means for holding the carrier arms and the jaws together.

ROBERT ARMSTRONG. 

